Lifting-magnet.



A. G. EASTWOOD. LIFTING MAGNET.

APPLICATION FILED JUNE 11, 1906.

927,513. f Patent edJuly13,1909.

2 SHEETS-SHEET 1,.

WI ESSES: uuvsrn-on AT 'I'ORNEYE A. G. EASTWOOD.

LIFTING MAGNET. \\.A

APPLICATION FILED JUNB1L1906.

927,513. Ptented July 13, 1909.

2 SHEETS-S'HEET 2.

, INVENTOR MWM @2 W Z WWW ATTORNEYS UNITED STAIES PATENT OFFICE;

ARTHUR U. EASTWOOD, OF CLEVELAND, OHIO.

LIFTING-MAGNET.

7 Application filed June 11,

To all whom it inc-y concern:

Be 1t known that I, ARTHUR O. EASTWOOD,

a citizen of the United States, residing at- (Jleveland, in the countyof Ouyahoga and State of Ohio, have invented or discovered new'anduseful Improvements in Lifting- Magnets, of which the following is aspecification. I

My invention relates to certain new and useful improvements in theconstruction of lifting magnets.

The objects of my invention are to produce a lifting magnet, which willhave a maximum lifting capacity for a given expenditure of electricalenergy; which will be of minimum bulk and weight for a given liftingcapacity and which will be economically produced.

Referring to the drawings, Figure 1 is a side elevation of one form ofmy invention, and Figs. 2 and 3 are respectively, a vertical centralsection and a bottom plan thereof. Fig. 4 is a vertical central sectionof another form of my invention.

In Figs. 1, 2, and 3, the magnetic circuit of the magnet is made up of asingle steel casting A, which is circular in plan View as shown inFig.3. The casting is annular and incloses in an annular recess themagnetizing coil B. A cen ral hole 0 passes through the casting A for apurpose to be later described. The lower face I) of the outer ring ofthe framework A'forms one pole of the magnet and the lower face E of theinner ring forms a second pole. It will be seen that the, magnetizingwinding B issurrmmded on the top and both sides by the integral castingA. .A

plate of non-magnetic material F protects the lower face of the windingB. As will be seen in Fig. 3, the plate F is seated against theshoulders D and E in'the polar faces and E and is held thereto by screws(1 and 0. Where the magnet is to be used in damp laces, the rings ofpacking may be placed )etween the plate F and the shoulders againstwhich it seats.

In Fig. 4, a slightly different construction is shown, in which theouter edge of the plate F is seated in a shoulder in the polar face I)as before, while the inner edge of the plate Specification of LettersPatent,

Patented July 18, 19Q9. 1906. Serial No. 321,142.

turns upward in the form of a sleeve embracing the pole piece E andextends upward abutting against the top late of the magnet. In this casea hole'C as'o passes centrally through the casting A. This serves toplace the annular pole E on a relatively larger diameter, thus producinga relatively large pole area with a comparatively small thickness ofmetal in the pole. Heat from the winding B therefore passes more readilythrough the thinner wall which is provided and the surface of thecylindrical passage 0 is available for radiating and dissipating thisheat. It will be readily understood from an inspection of the drawingsthat while the coil Bis protected on all sides, it is surrounded bycomparatively thin: walls and the heat which is generated within maytherefore be readily dissipated. By this means it is possible to workthe winding at 'a higher current density, thus producing a greaterlifting capacity for a given weight of magnet, at the same time sincethere are no joints in the magnetic circuit of the magnet proper a givenflux may be produced with a smaller expenditure of electrical energythan would be the case if the magnetic circuit were made up of a num berof pieces bolted together.

1 claim for my invention 1. In a lifting magnet, a, framework of circuitof the magnet,-said framework empoles d ependmg from the to p-plate, onepole being surrounded by the other, and a magnetizing coil in thespacebetween the poles, the inner pole having a hollow to dissipate heat andto increase the lifting capacity of 'the magnet in proportion to itsweight.

2. In a lifting magnet, the combination of an annular center pole, anannular concen trio outer pole, a magnetic frame or yoke connecting thepoles at one end thereof, and an energizing winding, said poles andframe forming a protecting pocket or chamber for the winding.

nctic frame, a flange extending from the inmagnetic materialconstituting the magnetic bracing a top plate, and a pair of spaced 3.In a lifting magnet, an annular flat mag ner edge-of the frame andforming an im1er a osed within the ohsuuber of the frame and forming anouter pole, and formed by the yoke and the pole pieces. an energizingWinding ithin the chamber Signed. at Cleveland Ohio this 25th day offormed between the frame and poles. May, A. D., 1906.

4. In alifting magnet, in tubular inner poie ARTHUR C. EASTWOOD. piece,it tubular outer pole piece surrounding Witnesses: the inner polepieceya yoke or frame connect- J. E. VVELLMAN ing the pole pieces at oneend, and an ener- I C. PIR'ILE.

ole, a fian e extending from the outer edge gizing winding disp

